chore: migrate java-storage-nio to monorepo #17053

Job	Run time
gapic-bom	1m 59s
owlbot-py	1m 27s
gitignore_correctness	1m 18s
group_id_check_for_maps_libraries	7m 11s
root-pom	1m 42s
package_name_check	1m 3s
owlbot-yaml	1m 1s
generate-readme	1m 4s
	16m 45s

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